Mobile x-ray apparatus including a battery management system

ABSTRACT

Provided is a mobile X-ray apparatus including: an X-ray radiator configured to emit X-rays; a battery configured to supply power to the X-ray radiator; a charger configured to charge the battery; a battery management system (BMS) configured to receive power from the battery or the charger and output a first signal based on a state of the battery; and a first switch configured to be turned off according to the first signal to prevent power from being supplied to the BMS, wherein the first switch is further configured to be turned on by power supplied from the charger when the BMS is shut down.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/391,957, filed on Dec. 28, 2016 (now U.S. Pat. No. 9,992,853), whichclaims the benefit of Korean Patent Application No. 10-2016-0099134,filed on Aug. 3, 2016, and Korean Patent Application No.10-2016-0181361, filed on Dec. 28, 2016 in the Korean IntellectualProperty Office, the disclosures of which are incorporated herein intheir entirety by reference.

BACKGROUND 1. Field

The present disclosure relates to mobile X-ray apparatuses includinglithium ion batteries.

2. Description of the Related Art

X-rays are electromagnetic waves having wavelengths of 0.01 to 100angstroms (Å), and are widely used, due to their ability to penetrateobjects, in medical apparatuses for imaging the inside of a living bodyor in non-destructive testing equipment for industrial use.

An X-ray apparatus using X-rays may obtain X-ray images of an object bytransmitting X-rays emitted from an X-ray source through an object anddetecting a difference in intensities of the transmitted X-rays via anX-ray detector. The X-ray images may be used to examine an internalstructure of an object and diagnose a disease of the object. The X-rayapparatus facilitates observation of an internal structure of an objectby using a principle in which penetrating power of an X-ray variesdepending on the density of the object and atomic numbers of atomsconstituting the object. As a wavelength of an X-ray decreases,penetrating power of the X-ray increases and an image on a screenbecomes brighter.

Since an X-ray radiator and an X-ray detector of the X-ray apparatus aregenerally affixed to a specific space, a patient needs to be transferredto an examination room where the X-ray apparatus is located for X-rayimaging.

However, a general X-ray apparatus has difficulty in performing X-rayimaging examinations on patients with mobility problems. Thus, a mobileX-ray apparatus has been developed to perform X-ray imaging withoutspace limitations.

In the mobile X-ray apparatus, an X-ray radiator is mounted on a movablemain body, and a portable X-ray detector is used. Due to thisconfiguration, the mobile X-ray apparatus may be taken directly to apatient with reduced mobility in order to perform X-ray imaging.

SUMMARY

Provided are apparatuses for waking up a battery management system (BMS)that is shut down by supplying power to the battery management system(BMS).

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect of an embodiment, a mobile X-ray apparatusincludes: battery configured to supply power to an X-ray radiator; acharger configured to charge the battery; a battery management system(BMS) configured to determine a state of the battery by detecting atleast one of a voltage and a temperature of the battery and output afirst signal that is a shut down signal based on the determined state ofthe battery; a direct current DC-to-DC (DC-DC) converter configured toconvert the power supplied by the battery into a driving power fordriving the battery management system (BMS); and a first switchcomprising a field effect transistor (FET) and configured to be turnedoff according to the first signal to prevent power from being suppliedto the DC-DC converter, wherein the battery management system (BMS) isfurther configured to be shut down when the first switch is turned off,and the first switch is further configured to be turned on by powersupplied from the charger when the battery management system (BMS) isshut down.

The mobile X-ray apparatus may further include a second switchconfigured to be turned on or off based on the first signal output fromthe battery management system (BMS), and the first switch is furtherconfigured to be turned on as the second switch is turned on.

The battery management system (BMS) is further configured to output adriving power for operating the second switch.

The second switch is further configured to be turned off when thebattery management system (BMS) is shut down.

The battery management system (BMS) is further configured to output athird signal, and the first switch is further configured to be turned onby the third signal.

The mobile X-ray apparatus may further include a third switch configuredto be turned on by the power supplied by the charger when the batterymanagement system (BMS) is shut down.

The mobile X-ray apparatus may further include a fourth switchconfigured to remain in an on-state in the absence of a driving powerand have one terminal connected to the third switch to control the thirdswitch.

The battery management system (BMS) is further configured to output adriving power for operating the fourth switch.

The mobile X-ray apparatus may further include a discharge FETconfigured to be turned on or off based on a signal output from thebattery management system (BMS) and to be turned on when the battery isdischarged and be turned off when the battery is charged.

The discharge FET is further configured to, when turned off, form acurrent path from a minus terminal of the battery to the charger.

The mobile X-ray apparatus may further include a charge FET configuredto be turned on or off based on a signal output from the batterymanagement system (BMS) and to be turned on when the battery is chargedand be turned off when the battery is discharged.

The charge FET is further configured to, when turned off, form a currentpath from the X-ray radiator to a minus terminal of the battery.

The battery may be a lithium ion battery.

According to another aspect of an embodiment, a mobile X-ray apparatusincludes: an X-ray radiator configured to emit X-rays; a batteryconfigured to supply power to the X-ray radiator; a battery managementsystem (BMS) configured to be shut down based on a state of the battery;and a charger configured to supply power to the battery and the batterymanagement system (BMS), wherein the battery management system (BMS) isfurther configured to be woken up by the power that is supplied from thecharger when the battery management system (BMS) is shut down.

The mobile X-ray apparatus may further include a physical switchprotruding outward therefrom, and the battery management system (BMS)may be woken up by the physical switch when the battery managementsystem (BMS) is shut down.

According to an embodiment, the mobile X-ray apparatus may wake up thebattery management system (BMS) that is shut down without using aseparate switch by disconnecting an AC power cord provided on a mainbody from an outlet and then inserting the AC power cord into theoutlet.

According to another embodiment, a wakeup switch may be provided on themain body of the mobile X-ray apparatus and be used to wake up theshutdown battery management system (BMS).

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIGS. 1A through 1C are external views and block diagrams of X-rayapparatuses implemented as mobile X-ray apparatuses, according toembodiments;

FIG. 2 is an external view of an X-ray detector included in each of theX-ray apparatuses of FIGS. 1A through 1C;

FIG. 3 is a block diagram of an X-ray apparatus according to anembodiment;

FIG. 4 illustrates components of a power supply included in a mobileX-ray apparatus, according to an embodiment;

FIG. 5 is a schematic diagram illustrating discharging of a lithium ionbattery according to an embodiment;

FIG. 6 is a schematic diagram illustrating charging of a lithium ionbattery according to an embodiment;

FIG. 7 is a detailed block diagram of a mobile X-ray apparatus accordingto an embodiment;

FIG. 8 illustrates a shutdown process performed by a mobile X-rayapparatus according to an embodiment; and

FIGS. 9 and 10 illustrate shut down circuits and neighboring elementsaccording to embodiments.

DETAILED DESCRIPTION

Various embodiments will be described more fully hereinafter withreference to the accompanying drawings. The embodiments and terms usedherein are not intended to limit technologies described in the presentdisclosure to particular implementations, and the scope of the presentdisclosure should be construed as including all the changes,equivalents, and substitutions made to the embodiments. In theaccompanying drawings, like reference numerals refer to like elementsthroughout.

Use of singular forms includes plural references as well unlessexpressly specified otherwise. As used herein, the expression such as “Aor B” or “at least one of A and/or B” includes any and all combinationsof one or more of the associated listed items. It will be understoodthat the terms “first”, “second”, etc. may be used herein to describevarious elements or components regardless of the order or priority amongthe elements or components. The terms may only be used to distinguishone element or component from another element or component withoutlimiting the elements or components. Expressions such as “at least oneof,” when preceding a list of elements, modify the entire list ofelements and do not modify the individual elements of the list.Hereinafter, the operating principles and embodiments of the presentdisclosure will be described in detail with reference to theaccompanying drawings.

Throughout the specification, it should be noted that when an element(e.g., a first element) is referred to as being “connected” or “coupled”(functionally or via a communication network) to another element (e.g.,a second element), it can be connected or coupled to the other elementdirectly or via another element (e.g., a third element).

In the present specification, the expression “configured (or set) to”may be interchangeably used with, for example, “suitable for,” “havingthe capacity to,” “adapted to,” “made to,” “capable of,” or “designedto” in hardware or software, depending on the circumstances. In somecases, the expression “a device configured to” may mean that the device“is capable of” doing something together with other devices orcomponents. For example, the phrase “a processor configured (or set) toperform operations A, B, and C” may mean a dedicated processor (e.g.,embedded processor) for performing the corresponding operations or ageneral-purpose processor (e.g., a central processing unit (CPU) or anapplication processor (AP)) that can perform the correspondingoperations by executing one or more software programs stored in a memorydevice.

Throughout the specification, a “user” may be a person who manipulates amobile X-ray apparatus. Furthermore, the “user” may refer to a device(e.g., an artificial intelligence (AI) electronic device, a robot, orthe like) for performing manipulation of the mobile X-ray apparatus.

The term ‘part’ or ‘portion’ used herein may be implemented usinghardware or software, and according to embodiments, a plurality of‘parts’ or ‘portions’ may be formed as a single unit or element, or one‘part’ or ‘portion’ may include a plurality of units or elements.

In the present specification, an image may include a medical imageobtained by a magnetic resonance imaging (MRI) apparatus, a computedtomography (CT) apparatus, an ultrasound imaging apparatus, an X-rayimaging apparatus, or another medical imaging apparatus.

Furthermore, in the present specification, an ‘object’ may be a targetto be imaged and include a human, an animal, or a part of a human oranimal. For example, the object may include a body part (an organ, etc.)or a phantom.

Hereinafter, the operating principles and embodiments of the presentdisclosure will be described in detail with reference to theaccompanying drawings.

FIGS. 1A through 1C are external views and block diagrams of X-rayapparatuses 100 implemented as mobile X-ray apparatuses, according toembodiments.

Referring to FIG. 1A, the X-ray apparatus 100 according to the presentembodiment includes an X-ray radiator 110 for generating and emittingX-rays, an input device 151 for receiving a command from a user, adisplay 152 for providing information to the user, a controller 120 forcontrolling the X-ray apparatus 100 according to the received command,and a communication unit 140 for communicating with an external device.

The X-ray radiator 110 may include an X-ray source for generating X-raysand a collimator for adjusting a region irradiated with the X-raysgenerated by the X-ray source.

When the X-ray apparatus 100 is implemented as a mobile X-ray apparatus,a main body 101 connected to the X-ray radiator 110 is freely movable,and an arm 103 connecting the X-ray radiator 110 and the main body 101to each other is also rotatable and linearly movable. Thus, the X-rayradiator 110 may be moved freely in a three-dimensional (3D) space.

The input device 151 may receive commands for controlling imagingprotocols, imaging conditions, imaging timing, and locations of theX-ray radiator 110. The input device 151 may include a keyboard, amouse, a touch screen, a voice recognizer, etc.

The display 152 may display a screen for guiding a user's input, anX-ray image, a screen for displaying a state of and the like.

The controller 120 may control in the X-ray apparatus 100, agingconditions and imaging timing of the X-ray radiator 110 according to acontrol command input by the user and generate a medical image based onimage data received from an X-ray detector 200. Furthermore, thecontroller 120 may control a position or orientation of the X-rayradiator 110 according to imaging protocols and a position of an object.

The controller 120 may include a memory configured to store programs forperforming the above operations of the X-ray apparatus 100 as well asoperations thereof that will be described below and a processorconfigured to execute the stored programs. The controller 120 mayinclude a single processor or a plurality of processors. When thecontroller 120 includes the plurality of processors, the plurality ofprocessors may be integrated onto a single chip or be physicallyseparated from one another.

A holder 105 may be formed on the main body 101 so as to accommodate theX-ray detector 200. Furthermore, a charging terminal is disposed in theholder 105 so as to charge the X-ray detector 200. In other words, theholder 105 may be used not only to accommodate but also to charge theX-ray detector 200.

The input device 151, the display 152, the controller 120, and thecommunication unit 140 may be provided on the main body 101. Image dataacquired by the X-ray detector 200 may be transmitted to the main body101 for image processing, and then the resulting image may be displayedon the display 152 or transmitted to an external device via thecommunication unit 140.

Furthermore, the controller 120 and the communication unit 140 may beseparate from the main body 101, or only some components of thecontroller 120 and the communication unit 140 may be provided on themain body 101.

The X-ray apparatus 100 may be connected to external devices such as anexternal server 31, a medical apparatus 32, and a portable terminal 33(e.g., a smart phone, a tablet PC, or a wearable device) in order totransmit or receive data via the communication unit 140.

The communication unit 140 may include at least one component thatenables communication with an external device. For example, thecommunication unit 140 may include at least one of a local areacommunication module, a wired communication module, and a wirelesscommunication module

Furthermore, the communication unit 140 may receive a control signalfrom an external device and transmit the received control signal to thecontroller 120 so that the controller 120 may control the X-rayapparatus 100 according to the received control signal.

Alternatively, by transmitting a control signal to an external devicevia the communication unit 140, the controller 120 may control theexternal device according to the transmitted control signal. Forexample, the external device may process data according to a controlsignal received from the controller 120 via the communication unit 140.

Furthermore, the communication unit 140 may further include an internalcommunication module that enables communications between components ofthe X-ray apparatus 100. A program for controlling the X-ray apparatus100 may be installed on the external device and may include instructionsfor performing some or all of the operations of the controller 120.

The program may be preinstalled on the portable terminal 33, or a userof the portable terminal 33 may download the program from an externalserver 31 providing an application for installation. The external server31 for providing an application may include a recording medium havingthe program recorded thereon.

In addition, the main body 101 may be equipped with an alternatingcurrent (AC) power cord 750 and/or a switch 716. The user may connectthe AC power cord 750 to an outlet (not shown) when a battery managementsystem (BMS) is shut down to wake up the battery management system (BMS)from shutdown. Furthermore, the user presses the switch 716 when thebattery management system (BMS) is shut down to wake up the batterymanagement system (BMS) from shutdown.

According to embodiments, the user may use one of the AC power cord 750and the switch 716 in the main body 101 to wake up the batterymanagement system (BMS) that is shut down.

Referring to FIG. 1B, a main body 101 includes an AC power cord 750 butis not equipped with the switch (716 of FIG. 1A). In this case, the usermay wake up a battery management system (BMS) that is shut down byconnecting the AC power cord 750 to an outlet (not shown).

Referring to 1C, a main body 101 is equipped with a switch 716. In thiscase, the user may press the switch 716 when a battery management system(BMS) is shut down to wake up the shutdown battery management system(BMS). The switch 716 may be positioned on outside of a holder 105 foraccommodating an X-ray detector 200 or on a side of the main body 101.

FIG. 2 is an external view of the X-ray detector 200.

As described above, the X-ray detector 200 used in the X-ray apparatus100 may be implemented as a portable X-ray detector. In this case, theX-ray detector 200 may be equipped with a battery for supplying power tooperate wirelessly, or as shown in FIG. 2, may operate by connecting acharge port 201 to a separate power supply via a cable C.

A case 203 maintains an external appearance of the X-ray detector 200and has therein a plurality of detecting elements for detecting X-raysand converting the X-rays into image data, a memory for temporarily orpermanently storing the image data, a communication module for receivinga control signal from the X-ray apparatus 100 or transmitting the imagedata to the X-ray apparatus 100, and a battery. Furthermore, imagecorrection information and intrinsic identification (ID) information ofthe X-ray detector 200 may be stored in the memory, and the stored IDinformation may be transmitted together with the image data duringcommunication with the X-ray apparatus 100.

FIG. 3 is a block diagram of an X-ray apparatus 100 according to anembodiment.

Referring to FIG. 3, the X-ray apparatus 100 according to the presentembodiment may include an X-ray radiator 305, a controller 310, a powersupply 320 including a lithium ion battery 322, and a charger 330. TheX-ray apparatus 100 may further include a high voltage generator (notshown) provided on a main body. The X-ray apparatus 100 of FIG. 3 may beimplemented as a mobile X-ray apparatus as shown in FIG. 1A, and FIG. 3illustrates only components related to the present embodiment. Thus, itwill be understood by those of ordinary skill in the art that the X-rayapparatus 100 may further include common components other than thoseshown in FIG. 3.

The descriptions with respect to the X-ray radiator 110 in FIG. 1A mayapply to descriptions with respect to the X-ray radiator 305, and thus,are not repeated. Furthermore, the descriptions with respect to thecontroller 120 in FIG. 1A may apply to descriptions with respect to thecontroller 310, and thus, are not repeated.

The power supply 320 may supply power to a load via the lithium ionbattery 322. For example, the load may include the X-ray radiator 305,the controller 310, and various other components of the X-ray apparatus100, to which power is supplied. In other words, the lithium ion battery322 may supply operating power to the X-ray radiator 305 and thecontroller 310.

Furthermore, the power supply 320 may supply, via the lithium ionbattery 322, operating power to components of the X-ray apparatus 100that require the operating power. For example, the power supply 320 maysupply operating power to the input device 151, the display 152, and thecommunication unit 140 of the X-ray apparatus 100 via the lithium ionbattery 322.

The power supply 320 may control overcurrent that occurs during emissionof X-rays by the X-ray radiator 305. In other words, as the X-rayradiator 305 emits X-rays, overcurrent that is higher than a normaloperating current may flow in the power supply 320, and the power supply320 may control the overcurrent. According to an embodiment, in order tocontrol overcurrent, the power supply 320 may construct a circuitconsisting of a discharge field effect transistor (FET) having FETsconnected in parallel and a charge FET. According to another embodiment,in order to control the overcurrent, the power supply 320 may constructa circuit including current sensors having different capacities formeasuring the amount of discharge current.

The charger 330 may charge the power supply 320. In detail, the charger330 may supply a charging power to charge the lithium ion battery 322 ofthe power supply 320. In this case, the charging power may be a powergenerated by the charger 330. According to an embodiment, the charger330 may be combined with an external power supply to receive power fromthe external power supply. The charger 330 may then control the receivedpower according to a user input or arithmetic operations performedwithin the X-ray apparatus 100, to supply a charging power to thelithium ion battery 322.

The power supply 320, the charger 330, and the controller 310 may eachinclude a communication interface that enables communicationtherebetween. For example, the power supply 320, the charger 330, andthe controller 310 may communicate with one another via theircommunication interfaces according to a controller area network (CAN)protocol. Furthermore, according to another embodiment, communicationsmay be performed among the power supply 320, the charger 330, and thecontroller 310 by using a high-speed digital interface such as lowvoltage differential signaling (LVDS), an asynchronous serialcommunication protocol such as a universal asynchronous receivertransmitter (UART), a low-latency network protocol such as an errorsynchronous serial communication protocol, or other variouscommunication methods that are obvious to those of ordinary skill in theart. Furthermore, the power supply 320, the charger 330, and thecontroller 310 may each be constituted by a different module. Thus,since the controller 310 does not need to directly monitor a highvoltage, a high voltage circuit is not needed within the controller 310.This may consequently reduce the risks associated with the high voltagecircuit, thereby effectively improving stability.

In detail, in a mobile X-ray apparatus using a conventional lead-acidbattery, a controller 310 may include a circuit for monitoring a highvoltage state, and may be damaged by high voltages. On the other hand,in the X-ray apparatus 100 according to the present embodiment, abattery management system (BMS) of the power supply 320 may monitor ahigh voltage state and transmit the high voltage state to the controller310. This configuration may reduce the risk of damage to the controller310.

Furthermore, when the power supply 320, the charger 330, and thecontroller 310 are each composed of a different module, they may be usedfor different mobile X-ray apparatuses and thus share a common platform.Furthermore, by applying a shield case to each of the power supply 320,the charger 330, and the controller 310, it is possible to suppressElectro Magnetic Interference (EMI)/Electro Magnetic Compatibility (EMC)noise that may occur therebetween.

FIG. 4 illustrates components of a power supply 320 included in a mobileX-ray apparatus 100, according to an embodiment.

Referring to FIG. 4, the power supply 320 may include a lithium ionbattery 322, a battery management system (BMS) 410, a discharge FET 430,and a charge FET 440. The power supply 320 shown in FIG. 4 includes onlycomponents related to the present embodiment. Furthermore, the powersupply 320 may include a voltage sensor (not shown) for detecting avoltage and a temperature sensor (not shown) for detecting atemperature. Thus, one of ordinary skill in the art will understand thatthe power supply 320 may further include common components other thanthose shown in FIG. 4.

The lithium ion battery 322 is a type of secondary battery and consistsof three components: an anode, a cathode, and an electrolyte. Forexample, lithium cobalt oxide (LiCoO₂) or lithium iron phosphate(LiFePO₄) may be used for the anode, and graphite may be used for thecathode. The lithium ion battery 322 may include a combination of aplurality of battery cells connected to each other. For example, thelithium ion battery 322 may include a total of three hundred andfifty-two (352) cells, i.e., a serial connection of 88 cells and aparallel connection of 4 cells.

Furthermore, the lithium ion battery 322 may be suitable for use in amobile X-ray apparatus 100 due to its smaller size and lighter weightthan conventional lead-acid batteries. For example, since a total massof the power supply 320 including the lithium ion battery 322 and aperipheral circuit may be 33.2 kg, the total mass may be less than 35kg, which is the maximum allowable gross mass for carrying on anaircraft. Thus, the power supply 320 may be transported by air as asingle component.

The mobile X-ray apparatus 100 may supply power to an X-ray radiator 305through a battery, and may include the battery management system (BMS)410 configured to operate a protection circuit by checking a voltage anda temperature of the battery.

The battery management system (BMS) 410 may detect a state of thelithium ion battery 322, such as a voltage and a temperature thereof.According to an embodiment, the battery management system (BMS) 410 mayinclude a battery stack monitor circuit 412 designed to monitor avoltage of the lithium ion battery 322 and a temperature of a batterycell. The battery management system (BMS) 410 may control and manage thepower supply 320 based on the state of the lithium ion battery 322.Furthermore, the battery management system (BMS) 410 may control on/offstates of the charge FET 440 and the discharge FET 430 to manage acharge path and a discharge path, respectively.

Furthermore, the battery management system (BMS) 410 may operate aprotection circuit based on the state of the lithium ion battery 322. Inother words, the battery management system (BMS) 410 may operate, basedon the state of the lithium ion battery 322, the protection circuit toprotect the lithium ion battery 322 from dangerous conditions. Indetail, based on the state of the lithium ion battery 322, the batterymanagement system (BMS) 410 may operate the protection circuit toprotect the lithium ion battery 322 against at least one ofover-discharge, overcurrent, overheating, and unbalancing betweenbattery cells.

The battery management system (BMS) 410 may operate, based on the stateof the lithium ion battery 322, the protection circuit by checkingstates of over-discharge, overcurrent, overheating, and unbalancingbetween battery cells, and may accordingly be shut down.

The battery management system (BMS) 410 may operate the protectioncircuit when the lithium ion battery 322 is in an over-discharged statewhere a voltage of the lithium ion battery 322 is lower than a referencevoltage. For example, if a voltage of the lithium ion battery 322 dropsto less than or equal to 275 V, the battery management system (BMS) 410may operate a shutdown circuit to turn itself off. Furthermore, thebattery management system (BMS) 410 may operate the protection circuitwhen the lithium ion battery 322 is in an overcurrent state where acurrent of the lithium ion battery 322 is higher than a reference value.For example, if the current of the lithium ion battery 322 is greaterthan or equal to 40 A, the battery management system (BMS) 410 mayoperate a shutdown circuit to reset itself. The battery managementsystem (BMS) 410 may also operate the protection circuit when thelithium ion battery 322 is in an overheated state where a temperature ofthe lithium ion battery 322 is higher than a reference value. Forexample, if the temperature of the lithium ion battery 322 is greaterthan or equal to 70° C., the battery management system (BMS) 410 mayoperate the protection circuit to shut off a charge path and a dischargepath. Furthermore, when the lithium ion battery 322 is unbalancedbetween cells, the battery management system (BMS) 410 may operate theprotection circuit. For example, if a voltage difference between cellsin the lithium ion battery 322 remains greater than or equal to 0.5 Vfor ten (10) seconds or more, the battery management system (BMS) 410may operate a shutdown circuit to turn itself off.

The battery management system (BMS) 410 may communicate with acontroller 310 via a communication interface to monitor a state of thepower supply 320.

A load 406 may receive power via a charge path and/or a discharge path.

The discharge FET 430 may include a plurality of FETs connected inparallel. Since overcurrent may flow in the power supply 320 duringX-ray emission by the X-ray radiator 305, the FETs having a specificcapacity in the discharge FET 430 may be connected in parallel. In otherwords, by connecting the FETs having the specific capacity in parallel,a maximum allowable current capacity of the discharge FET 430 may beincreased. For example, if overcurrent greater than or equal to 300 Aflows within the power supply 320 during X-ray emission by the X-rayradiator 305, the discharge FET 430 may be constituted by four (4)parallel connected FETs having a capacity of 100 A for protectionagainst the overcurrent.

According to an embodiment, the discharge FET 430 and the charge FET 440may each be constituted by an N-channel FET.

The discharge FET 430 and the charge FET 440 may control a path ofdischarge or charge current when the lithium ion battery 322 isdischarged or charged. According to an embodiment, when the lithium ionbattery 322 is discharged, the charge FET 440 may be turned off, and adischarge current loop may be formed by the discharge FET 430. Accordingto another embodiment, when the lithium ion battery 322 is charged, thedischarge FET 430 may be turned off, and a charge current loop may beformed by a body diode of the discharge FET 430 and the charge FET 440.Furthermore, the lithium ion battery 322 may be discharged and chargedat the same time via the discharge FET 430 and the charge FET 440.

Furthermore, while FIG. 4 shows that a load 406 for receiving a powerfrom the lithium ion battery 322 includes the controller 310 and theX-ray radiator 305, the load 406 may further include other components ofthe X-ray apparatus 100 that require power.

FIG. 5 is a schematic diagram illustrating discharging of a lithium ionbattery 322 according to an embodiment.

An on/off state of a discharge FET 430 may be controlled based on asignal output from a battery management system (BMS) 410. In detail, thedischarge FET 430 may be turned on when the lithium ion battery 322 isdischarged and be turned off when the lithium ion battery 322 ischarged. The signal may be coupled to a gate terminal of the dischargeFET 430. When the discharge FET 430 is turned off, a current path isformed from a minus terminal of the lithium ion battery 322 to a charger330 via a body diode.

In detail, when the lithium ion battery 322 is discharged, a charge FET440 may be turned off since a source (S) voltage of the charge FET 440is higher than a drain (D) voltage thereof. Furthermore, when thelithium ion battery 322 is discharged, a discharge FET 430 may be turnedon since a drain (D) voltage of the discharge FET 430 is higher than asource (S) voltage thereof.

Thus, as shown in FIG. 5, a discharge current loop may be formed in aclockwise direction in which a discharge current flows through a load406, the discharge FET 430, and the lithium ion battery 322.Furthermore, even when the charge FET 440 is turned off, discharging ofthe lithium ion battery 322 may be performed normally.

FIG. 6 is a schematic diagram illustrating charging of a lithium ionbattery 322 according to an embodiment.

An on/off state of a charge FET 440 may be controlled based on a signaloutput from a battery management system (BMS) 410. In detail, the chargeFET 440 may be turned on when the lithium ion battery 322 is charged andbe turned off when the lithium ion battery 322 is discharged. When thecharge FET 440 is turned off, a current path from the load 406 to aminus terminal of the lithium ion battery 322 may be formed.

In detail, when the lithium ion battery 322 is charged, a discharge FET430 may be turned off since a source (S) voltage of the discharge FET430 is higher than a drain (D) voltage thereof. When the discharge FET430 is turned off, a charge current may flow through a body diode of thedischarge FET 430. Furthermore, when the lithium ion battery 322 ischarged, the charge FET 440 may be turned on since a drain (D) voltageof the charge FET 440 is higher than a source (S) voltage thereof.

Thus, as shown in FIG. 6, a charge current loop may be formed in acounter-clockwise direction in which a charge current flows through acharger 330, the lithium ion battery 322, the body diode of thedischarge FET 430, and the charge FET 440. Furthermore, even when thedischarge FET 430 is turned off, charging of the lithium ion battery 322may be performed normally.

FIG. 7 is a detailed block diagram of a mobile X-ray apparatus 100according to an embodiment.

Referring to FIG. 7, a power supply 320 may include a lithium ionbattery 322, a battery management system (BMS) 410, a discharge FET 430,a charge FET 440, a shutdown circuit 710, a first current sensor 730, asecond current sensor 740, a DC-to-DC (DC-DC) converter 720, and a fuse760. Furthermore, the X-ray apparatus 100 may include a third currentsensor 751. Since the lithium ion battery 322, the battery managementsystem (BMS) 410, the discharge FET 430, and the charge FET 440respectively correspond to the lithium ion battery 322, the batterymanagement system (BMS) 410, the discharge FET 430, and the charge FET440 described with reference to FIG. 4, detailed descriptions thereofwill be omitted below. The first and second current sensors 730 and 740may include a Hall sensor, and the shutdown circuit 710 that is aprotection circuit may include a switching circuit such as a FET.

The battery management system (BMS) 410 may detect current of thelithium ion battery 322 by using different current sensors, i.e., thefirst and second current sensors 730 and 740. In detail, the batterymanagement system (BMS) 410 may detect current flowing in the lithiumion battery 322 by using the first current sensor 730. The first currentsensor 730 may be a small-capacity sensor for detecting a current havinga relatively low intensity. In other words, the first current sensor 730may be a sensor for detecting a current having an intensity less than orequal to a reference level. For example, the first current sensor 730may detect a current that is less than or equal to 50 A. Furthermore,when overcurrent flows in the lithium ion battery 322, the batterymanagement system (BMS) 410 may detect overcurrent flowing in thelithium ion battery 322 by using the second current sensor 740. Thesecond current sensor 740 may be a large-capacity sensor for detecting acurrent having a relatively high intensity. In other words, the secondcurrent sensor 740 may be a sensor for detecting a current having anintensity greater than or equal to a reference level. For example, thesecond current sensor 740 may detect a current that is greater than orequal to 300 A.

According to an embodiment, the battery management system (BMS) 410 maydetect, via the first current sensor 730, current flowing in the lithiumion battery 322 by activating the first current sensor 730 whiledeactivating the second current sensor 740. Then, when an X-ray radiator305 emits X-rays, the battery management system (BMS) 410 may detectovercurrent that occurs during the X-ray emission via the second currentsensor 740 by activating the second current sensor 740 whiledeactivating the first current sensor 730. Subsequently, when the X-rayemission is completed, the battery management system (BMS) 410 maydetect, via the first current sensor 730, current flowing in the lithiumion battery 322 by activating the first current sensor 730 whiledeactivating the second current sensor 740. According to an embodiment,the battery management system (BMS) 410 may receive an X-ray emissionpreparation signal from a controller 310 and activate the second currentsensor 740 to detect overcurrent occurring during X-ray emission via thesecond current sensor 740.

The battery management system (BMS) 410 may check the residual amount ofthe lithium ion battery 322 based on the amount of current detectedusing the first and second current sensors 730 and 740. In detail, thebattery management system (BMS) 410 may use Coulomb Counting BasedGauging to check the residual amount of the lithium ion battery 322based on the detected amount of current.

Furthermore, the mobile X-ray apparatus 100 may further include thethird current sensor 751 for measuring a charge current. In other words,the mobile X-ray apparatus 100 may further include the third currentsensor 751 at an output terminal of the charger 330. When the lithiumion battery 322 is charged and discharged at the same time, currentmeasured by the first or second current sensor 730 or 740 may be a sumof a discharge current and a charge current. Thus, in order toaccurately measure a discharge current and a charge current, the mobileX-ray apparatus 100 may measure the charge current by using the thirdcurrent sensor 751.

The battery management system (BMS) 410 may receive signals indicatingthat the X-ray radiator 305 starts emission of X-rays and that the X-rayradiator 305 completes the emission of X-rays from the controller 310via a communication interface.

The battery management system (BMS) 410 may output a first signal basedon a state of the lithium ion battery 322. The first signal may be ashut down signal that is applied to the shutdown circuit 710. Thebattery management system (BMS) 410 may turn itself off by using theshutdown circuit 710. When the battery management system (BMS) 410checks a state of the lithium ion battery 322 to detect hazardousconditions such as over-discharge and overcharge, the battery managementsystem (BMS) 410 may turn itself off by using the shutdown circuit 710that serves as a protection circuit. When the battery management system(BMS) 410 turns itself off, power being supplied to the controller 310is also cut off, so that the controller 310 may also turn off.

The fuse 760 is designed to stop continuous flowing of excessive currentthat is greater than a nominal value in the power supply 320 and mayprotect a battery cell when the lithium ion battery 322 is subjected toan external short circuit.

The DC-DC converter 720 may convert power supplied by the lithium ionbattery 322 into a DC power for driving the battery management system(BMS) 410.

FIG. 8 illustrates a shutdown process performed by the mobile X-rayapparatus 100 according to an embodiment. The shutdown process will nowbe described with reference to FIGS. 7 and 8.

Referring to FIGS. 7 and 8, the power supply 320, the controller 310,and the charger 330 may each include a communication interface andcommunicate with one another via their communication interfaces. Forexample, the power supply 320, the controller 310, and the charger 330may communicate with one another according to a CAN protocol.

The power supply 320 may include a first temperature sensor 820.

According to an embodiment, the power supply 320 may include the firsttemperature sensor 820 that is dedicated for use with the batterymanagement system (BMS) 410 and may be directly monitored by the batterymanagement system (BMS) 410. The battery management system (BMS) 410 mayuse the first temperature sensor 820 to monitor a temperature of thepower supply 320 and determine whether the power supply 320 isoverheated. For example, if the power supply 320 is overheated to atemperature higher than a specific threshold value, the batterymanagement system (BMS) 410 may control the charge FET 440 that is acharge controller and the discharge FET 430 that is a dischargecontroller to cut off a charge path and a discharge path and control aprotection circuit to turn off the battery management system (BMS) 410itself.

Furthermore, the power supply 320 may further include a secondtemperature sensor 810. According to an embodiment, the power supply 320may include the second temperature sensor 810 that is dedicated for usewith the controller 310 and may be directly monitored by the controller310. The second temperature sensor 810 may be provided on outside of thebattery management system (BMS) 410. If a communication error occursbetween the controller 310 and the battery management system (BMS) 410,the controller 310 may not be able to receive temperature information ofthe power supply 320 from the battery management system (BMS) 410. Inthis case, the controller 310 may monitor the temperature of the powersupply 320 via the second temperature sensor 810. Thus, when acommunication error occurs, the controller 310 may determine whether toturn off the power supply 320 by using the second temperature sensor 810regardless of the state of the battery management system (BMS) 410.

The power supply 320 and the charger 330 may respectively includeinterrupt pins 831 and 833 that can be directly controlled by thecontroller 310. In other words, the controller 310 may respectivelytransmit disable signals to the power supply 320 and the charger 330 viathe interrupt pins 831 and 833, and accordingly turn off the powersupply 320 and the charger 330. Thus, when it is determined that atemperature of the power supply 320 is equal to or higher than aspecific threshold value via the second temperature sensor 810, thecontroller 310 may forcibly turn off the power supply 320 and thecharger 330 via the interrupt pins 831 and 833, respectively.

Furthermore, when the battery management system (BMS) 410 operates ashutdown circuit that is a protection circuit to turn itself off, a shutdown signal from the battery management system (BMS) 410 may betransmitted to the controller 310. After receiving the shut down signal,the controller 310 may monitor whether the battery management system(BMS) 410 is shut down for a specific amount of time. If the batterymanagement system (BMS) 410 is not shut down for the specific amount oftime as a result of monitoring, the controller 310 may forcibly turn offthe battery management system (BMS) 410 via the interrupt pin 831. Forexample, after the battery management system (BMS) 410 activates ashutdown bit, the controller 310 may monitor whether the batterymanagement system (BMS) 410 is shut down for ten (10) seconds. If thebattery management system (BMS) 410 is not shut down for 10 seconds, thecontroller 310 may forcibly turn off the battery management system (BMS)410 via the interrupt pin 831.

FIGS. 9 and 10 illustrate shut down circuits and neighboring elementsaccording to embodiments.

FIG. 9 shows a shutdown circuit 710, a DC-DC converter 720, and abattery management system (BMS) 410.

Referring to FIG. 9, the shutdown circuit 710 may include first throughfourth switches 712 through 715.

The first switch 712 may be implemented using a relay switch, a FET, oranother switching device. The first switch 712 may prevent power frombeing input to the DC-DC converter 720.

For example, the first switch 712 may be constituted by a FET and beturned on or off by a voltage applied to a gate terminal. When thebattery management system (BMS) 410 operates normally, the first switch712 may be turned on or off by a first signal 410 b, a second signal 410c, and/or a third signal 410 d that is/are output from the batterymanagement system (BMS) 410.

The second switch 713 may be driven by a DC power 410 a output from thebattery management system (BMS) 410 and may be turned on or off based onthe first signal 410 b. The first switch 712 may be turned on when thesecond switch 713 is turned on and be turned off when the second switch713 is turned off. The first signal 410 b may be a shut down signaloutput from the battery management system (BMS) 410 and for shuttingdown the battery management system (BMS) 410. The second switch 713 maybe turned off when the battery management system (BMS) 410 is shut down.For example, the second switch 713 may be implemented as a photocoupler,but is not limited thereto.

The third switch 714 may operate regardless of an operation of thebattery management system (BMS) 410, and may be turned on by power beingsupplied from the charger (330 of FIG. 7) when the battery managementsystem (BMS) 410 is shut down. For example, the third switch 714 may beformed as a photocoupler but is not limited thereto.

The fourth switch 715 may remain in the on-state in the absence of adriving power and have one terminal connected to the third switch 714 tocontrol an operation of turning on or off the third switch 714. When thefourth switch 715 is turned on, the third switch 714 may also be turnedon. When the fourth switch 715 is turned off, the third switch 714 mayalso be turned off. The fourth switch 715 may be driven by the DC power410 a output from the battery management system (BMS) 410. For example,the fourth switch 715 may be formed as a photocoupler but is not limitedthereto.

When operating normally, the battery management system (BMS) 410 mayoutput the DC power 410 a and the first through third signals 410 bthrough 410 d.

The DC power 410 a may be a driving power for operating the firstthrough fourth switches 712 through 715.

The first signal 410 b is a shut down signal for shutting down thebattery management system (BMS) 410 and is coupled to one terminal ofthe second switch 713 to control an on or off state of the second switch713. For example, if the battery management system (BMS) 410 operatesnormally, the first signal 410 b may remain in a logic low state to turnon the second switch 713. If the battery management system (BMS) 410 isshut down, the first signal 410 b may change to a logic high state toturn off the second switch 713.

The second signal 410 c is coupled to one terminal of the fourth switch715 and may turn off the fourth switch 715 when it is in a logic lowstate.

The third signal 410 d is coupled to the gate terminal of the firstswitch 712 and may turn on the first switch 712 when it is in a logiclow state.

The shutdown circuit 710 may shut down the battery management system(BMS) 410 by preventing power from being input to the DC-DC converter720 in response to the third signal 410 d output from the batterymanagement system (BMS) 410. When the battery management system (BMS)410 is shut down, power is prevented from being supplied to the batterymanagement system (BMS) 410, and accordingly the battery managementsystem (BMS) 410 may be turned off.

An operation of the shutdown circuit 710 when the battery managementsystem (BMS) 410 operates normally is now described.

During normal operation, the battery management system (BMS) 410 mayoutput the first signal 410 b in a logic low state and the second signal410 c in a logic high state.

The DC power 410 a may be applied to one terminal of the second switch713, and the first signal 410 b that is in a logic low state may beapplied to the other terminal thereof, so that the second switch 713 maybe turned on. When the battery management system (BMS) 410 operatesnormally, the second switch 713 may turn on or off the first switch 712.

As the second switch 713 is turned on, a current path 717 is formed.Furthermore, since a lower voltage is applied to the gate terminal ofthe first switch 712 than to a source terminal due to the presence ofresistors 791 and 792, the first switch 712 is turned on, and powerapplied to a terminal 711 may be supplied to the battery managementsystem (BMS) 410 via the DC-DC converter 720.

In addition, the fourth switch 715 may be turned on in the absence ofthe DC power 410 a. The fourth switch 715 may be turned off when the DCpower 410 a is applied and then the second signal 410 c in a logic lowstate is applied. When the fourth switch 715 is turned off, currentcannot flow into a control terminal of the third switch 714, and thusthe third switch 714 may be turned off. In other words, when the batterymanagement system (BMS) 410 operates normally, the first switch 712 maybe controlled by the DC power 410 a and control signals, i.e., the firstthrough third signals 410 b through 410 d to remain in the on-state.

An operation of shutting down the battery management system (BMS) 410under abnormal conditions is now described.

When overcharge, over-discharge, or overheating of a battery isdetected, the battery management system (BMS) 410 may output the firstsignal 410 b in a logic high state and shut down the battery managementsystem (BMS) 410 itself, i.e. by preventing power from being suppliedthereto.

As the first signal 410 b changes from a logic low state to a logic highstate, the second switch 713 is turned off. When the second switch 713is turned off, the gate terminal of the first switch 712 is open, so thefirst switch 712 is turned off to prevent power from being supplied tothe DC-DC converter 720 and to the battery management system (BMS) 410.Accordingly, the battery management system (BMS) 410 is shut down.

When the battery management system (BMS) 410 is shut down, the DC power410 a for driving the second through fourth switches 713 through 715 andthe first through third signals 410 b through 410 d are not output.

A process of waking up the battery management system (BMS) 410 aftershutdown is now described. A wakeup operation may mean supplying powerso as to normally operate the battery management system (BMS) 410. Afterthe battery management system (BMS) 410 is shut down, a discharge pathfor a battery is cut off, so that power is not supplied from thebattery.

In this case, when the AC power cord (750 of FIG. 1A) is connected to anoutlet (not shown) in order to normally operate the battery managementsystem (BMS) 410, power may be applied to the terminal 711 via thecharger 330.

When the fourth switch 715 is turned on and power is applied to theterminal 711 after the battery management system (BMS) 410 is shut down,power is applied to the third switch 714 via the resistors 791 and 792to create a current path 718. The third switch 714 may then be turned onto create the current path 717. As the current paths 717 and 718 areformed, power is applied to the gate terminal of the first switch 712via the resistor 791, and the first switch 712 is turned on. When thefirst switch 712 is turned on, power is applied to the batterymanagement system (BMS) 410 via the DC-DC converter 720, and the batterymanagement system (BMS) 410 is able to operate normally. In other words,when power is supplied to the power supply 320 via the charger 330 byconnecting the AC power cord 750 when the battery management system(BMS) 410 is shut down, the battery management system (BMS) 410 may beautomatically turned on.

FIG. 10 illustrates a shutdown circuit 710 and neighboring elementsaccording to an embodiment.

In detail, FIG. 10 shows the shutdown circuit 710, a DC-DC converter720, and a battery management system (BMS) 410.

Referring to FIG. 10, the shutdown circuit 710 may include first throughfifth switches 712 through 716.

Descriptions of operations of the first through fourth switches 712through 715 that are already provided with respect to FIG. 9 areomitted, and only an operation of the fifth switch 716 is now described.

The shutdown circuit 710 may include the fifth switch 716. The fifthswitch 716 may be a physical switch, and as the fifth switch 716operates, the battery management system (BMS) 410 may operate in thesame way as described with reference to FIG. 9. For example, the fifthswitch 716 may be a push switch that may turn on or off when pressed bythe user.

The fifth switch 716 may be provided on outside of the main body (101 ofFIG. 1A) and be pressed by the user.

The fifth switch 716 may wake up the battery management system (BMS) 410that is shut down.

The fifth switch 716 formed as a push switch has one terminal connectedto a gate terminal of the first switch 712 via the resistor 792 and theother terminal connected to a ground. If the user connects the AC powercord (750 of FIG. 1A) to an outlet (not shown) when the batterymanagement system (BMS) 410 is shut down, power may then be applied tothe terminal 711 while one terminal of the fifth switch 716 may begrounded when pressed by the user, thereby forming a current path 717.As the current path 717 is formed, a voltage drop may occur at the gateterminal of the first switch 712 to turn on the first switch 712, sothat power may be supplied to the battery management system (BMS) 410.The fifth switch 716 may protrude outward from the main body 101 of theX-ray apparatus 100, and the user may wake up the X-ray apparatus 100 byoperating the fifth switch 716 when the battery management system (BMS)410 is shut down.

Conventionally, when a battery management system (BMS) is shut downafter cutting off a charge path and a discharge path, an X-ray apparatusmay not operate due to safety concerns. In this case, even if power isapplied from outside a main body of the X-ray apparatus, the shutdownbattery management system (BMS) cannot be woken up by the power so thatcurrent does not flow through a charge path and a discharge path andconsequently the X-ray apparatus may fail to operate. However, accordingto the present embodiment, a battery management system (BMS) that isshut down may be woken up by connecting an AC power cord provided on amain body to an outlet, and an X-ray apparatus may accordingly operate.Furthermore, according to the present embodiment, it is possible to wakeup the shutdown battery management system (BMS) by pressing a switchprovided on the main body.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure as definedby the following claims. Accordingly, the above embodiments and allaspects thereof are examples only and are not limiting.

What is claimed is:
 1. A mobile X-ray apparatus comprising: an X-rayradiator configured to emit X-rays; a battery configured to supply powerto the X-ray radiator; a battery management system comprising a batterystack monitor circuit that is configured to monitor a condition of thebattery and to be shut down based on the monitored condition of thebattery; and a controller configured to receive a shutdown signal fromthe battery management system, monitor a current status of the batterymanagement system for a predetermined time period, and turn off thebattery management system based on the monitored current status of thebattery management system.
 2. The mobile X-ray apparatus of claim 1,wherein the controller is further configured to monitor at least one ofa voltage, a current, and a temperature of the battery.
 3. The mobileX-ray apparatus of claim 1, wherein the controller is further configuredto turn off the battery management system if the battery managementsystem is not shut down for the predetermined time period.
 4. The mobileX-ray apparatus of claim 1, further comprising a charger configured tosupply power to the battery and the battery management system, whereinthe battery management system is further configured to be woken up bythe power that is supplied from the charger when the battery managementsystem is turned off.